The physical characteristics of a stream include its competence, gradient, channel pattern, bank, order, speed, and type of flow (Webster). The physical characteristics of a stream can determine what types of organisms live there (Prophet 2005).
Competence - the maximum size of sediments it can carry at a certain velocity. The sediments of a stream include sand, silt, gravel, rock, cobble, or combinations of them (Webster).
Gradient - the slope of the stream measured by the height drop divided by distance (Webster).
Channel pattern
Straight - A stream is considered straight when the stream flow is below 1.2 times the direct straight distance. Straight streams usually occur when the the banks of the stream cannot be eroded away or when the gradient is very high.
Meander - Streams that meander go one direction and then turn to the opposite direction. Water inside the curve has a lower velocity than that of the outside, so the sediments are deposited on the inside forming bars. The water on the outside cuts the banks and the turns become amplified.
Braided - Braided streams occur in places where water is shallow and wide and the speed is too slow for the stream to continue to carry its sediments. The sediments are deposited as bars that become interwoven (Prophet 2005).
Channel Patterns (Zhan 2008)
Bank - The banks of streams can be made up of clay, mud, stones, rocks, or combinations of those materials. The erosion and deposition of sediments of the bank is also a physical characteristic (The NatureMapping Program 1996).
Size - The size of a stream can be measured in order, length, width, depth, watershed size, and discharge.
Length and depth do not give a good general overview of a stream, but they can be used to describe a certain spot on the stream.
Watershed size of a stream is the amount of land that drains to it.
Discharge is the amount of water flowing in a stream. The unit for discharge is usually L/s or m3/s. Discharge can be calculated using the flow continuity equation Q=WDV where Q is the discharge, W is the width, D is the depth, and V is the velocity. It can also be measured with a weir, flume, or a hydrograph (Webster).
Type of flow
Laminar - Smooth and straight channel, slow moving water all in the same direction, parallel streamlines, uniformed current (Webster).
Turbulent - Fast and crazy flow with eddies (Webster), can erode the channel, can increase the oxygen content of water, and can increase evaporation (Prophet 2005).
Pools and Riffle - In most streams, there is a pattern of riffles and pools.
Riffles occur in streams when the channel is located in a place where the ledges cannot be easily eroded or where there is deposition of rocks and gravel. The water is shallow with high velocity. The flow is turbulent due to the rocks and cobbles in the water.
Pools occur after a riffle where the ledges can be eroded and the gradient is smaller (Prophet 2005).
Describe how topography influences streams.
Topography is the gradient or slope of a stream. When the slope is steep, it is more likely that eroded soil will get into the stream. The topography of a stream also affects its velocity. A moderate speed will maintain the amount of oxygen and gravel/cobble substrate. A high speed will result in more erosion and a higher competence.
A place is considered steep if it has a slope of more than 20 degrees. In places with steep slopes, the runoff is fast, resulting in fast flooding. The bed sediments in streams that drain steep places are stable and large ranging from boulder to cobble. The sources of streams in these places are from runoff resulting from precipitation, snow, and/or lake storage.
Hilly places have slopes from 10 to 20 degrees. The runoff is quick and since hilly places are used for grazing or forestry, there can be a lot of erosion. Streams draining these places can have silt once in a while. This makes these streams unstable and unsuitable for invertebrates and algae. Streams draining from these places begin from runoff, springs from groundwater, and/or lake storages.
Rolling areas have slopes of 3 to 10 degrees. These places have a very diverse amount of organisms. This is because of the run-riffle-pool sequence. Pools are deep and slow while riffles are shallow and fast. Between the two is a continuum of habitats. The formation of riffles and pools is dependent on the size of sediments. Riffles tend to have gravel and cobble while pools have small sediments.
Flat places have slopes of less than 3 degrees. The streams here are very slow and the beds are made up of sands and silts. This makes these places unsuitable for many organisms. In places draining rolling or flat areas, the streams usually start from springs or wetlands (National Institute of Water and Atmospheric Research 2002).
Explain the influence of mountains on precipitation.
Mountains force the moist air to drop all of its water as it moves up and over the mountain. This results in one side of the mountain getting a lot of rain while the other side has little. The height of the mountain determines how much water it blocks (Campbell and Reese 2001).
Explain how vegetation affects storm water runoff.
Vegetation helps decrease the amount of storm water runoff. It intercepts and absorbs the excess rainfall. It also causes the runoff's path to meander, which allows more water to be absorbed by the soil. Runoff is harmful because on its way to a body of water, it picks up pollution, such as fertilizers ("Trees and Vegetation" 2007)
Delineate the boundaries of a watershed.
(Environmental Media 1998)
Describe factors that affect the quality of groundwater.
Groundwater is all of the water in the saturated zone. The saturated zone is the area below the water table. The water table is the level where all the spaces are filled with water and nothing else. The area above the water table is called the unsaturated zone. Spaces in the unsaturated zone are filled with both water and oxygen. Water here is called soil moisture. An aquifer is a formation of permeable material where a decent amount of water can be obtained through a well.
Groundwater is closely linked to the hydrologic or water cycle. The hydrologic cycle is the circulation of water and its transformations from the ground to the atmosphere. When precipitation occurs, some of the water goes into the ground water. This is called recharge. The amount of time the water remains underground, called the residence time, varies greatly, from a few days to 10,000 years. Discharge is when the groundwater goes back up to the surface.
Wetlands are also affected by groundwater in that wetlands in high latitudes are areas where recharge occurs and wetlands in low latitudes are places where discharge happens. Therefore, the quality of the groundwater greatly affects the quality of the wetland and all the organisms that live there.
The water quality of groundwater is assessed by measuring the amount of various substances in the water. It is measured in milligrams per liter (mg/L). Factors used to determine the water quality include the pH, the salinity, and the hardness (see Analyze the parameters of a watershed for more info). Generally, water near the surface is more saline and harder and the deeper the water, the more saline it becomes. The quality of groundwater is greatly affected by the soil, the precipitation water, and then conditions of the rocks where the groundwater flows. For example, places near the coasts have groundwater with more sodium chlorine, and places near industry have groundwater with sulfur and nitrogen compounds obtained from the air.
Groundwater is polluted by point sources and non-point sources. Point sources include livestock wastes, leaks and spills of chemicals or petroleum, septic tanks, road salt, sewage sludge, from landfills. Non-Point Sources are pesticides, fertilizers, and other contaminants. These contaminants will end up in streams, rivers, and wetlands (Environment Canada 2008).
Another environmental problem with groundwater is the excess pumping of water for agriculture resulting in changes in the hydrologic cycle. The rate of evaporation from underground has increased and the depletion of groundwater has occurred in many areas (Campbell and Reese 2001).
Explain how the speed of water and vegetation cover relates to erosion.
Clearly, when the speed of water is faster, there is more force and erosion. When the speed of water is slower, more of the water is absorbed by the soil and there is less erosion (Environmental Protection Authority 2008).
Vegetation can slow down the process of erosion because its roots bind and stabilize to the soil. Without it, there is nothing to stop the soil from being eroded away.
Soil erosion is becoming a major environmental problem because when the soil is being eroded faster than it can be replaced, that place becomes infertile. Eventually, if no action is take to stop erosion, the area will become a desert ("Soil Erosion" 2005).
Analyze a stream's physical characteristics.
The physical characteristics of a stream include its competence, gradient, channel pattern, bank, order, speed, and type of flow (Webster). The physical characteristics of a stream can determine what types of organisms live there (Prophet 2005).Competence - the maximum size of sediments it can carry at a certain velocity. The sediments of a stream include sand, silt, gravel, rock, cobble, or combinations of them (Webster).
Gradient - the slope of the stream measured by the height drop divided by distance (Webster).
Channel pattern
Bank - The banks of streams can be made up of clay, mud, stones, rocks, or combinations of those materials. The erosion and deposition of sediments of the bank is also a physical characteristic (The NatureMapping Program 1996).
Size - The size of a stream can be measured in order, length, width, depth, watershed size, and discharge.
Type of flow
Pools and Riffle - In most streams, there is a pattern of riffles and pools.
Describe how topography influences streams.
Topography is the gradient or slope of a stream. When the slope is steep, it is more likely that eroded soil will get into the stream. The topography of a stream also affects its velocity. A moderate speed will maintain the amount of oxygen and gravel/cobble substrate. A high speed will result in more erosion and a higher competence.Explain the influence of mountains on precipitation.
Mountains force the moist air to drop all of its water as it moves up and over the mountain. This results in one side of the mountain getting a lot of rain while the other side has little. The height of the mountain determines how much water it blocks (Campbell and Reese 2001).Explain how vegetation affects storm water runoff.
Vegetation helps decrease the amount of storm water runoff. It intercepts and absorbs the excess rainfall. It also causes the runoff's path to meander, which allows more water to be absorbed by the soil. Runoff is harmful because on its way to a body of water, it picks up pollution, such as fertilizers ("Trees and Vegetation" 2007)Delineate the boundaries of a watershed.
(Environmental Media 1998)
Describe factors that affect the quality of groundwater.
Groundwater is all of the water in the saturated zone. The saturated zone is the area below the water table. The water table is the level where all the spaces are filled with water and nothing else. The area above the water table is called the unsaturated zone. Spaces in the unsaturated zone are filled with both water and oxygen. Water here is called soil moisture. An aquifer is a formation of permeable material where a decent amount of water can be obtained through a well.Groundwater is closely linked to the hydrologic or water cycle. The hydrologic cycle is the circulation of water and its transformations from the ground to the atmosphere. When precipitation occurs, some of the water goes into the ground water. This is called recharge. The amount of time the water remains underground, called the residence time, varies greatly, from a few days to 10,000 years. Discharge is when the groundwater goes back up to the surface.
Wetlands are also affected by groundwater in that wetlands in high latitudes are areas where recharge occurs and wetlands in low latitudes are places where discharge happens. Therefore, the quality of the groundwater greatly affects the quality of the wetland and all the organisms that live there.
The water quality of groundwater is assessed by measuring the amount of various substances in the water. It is measured in milligrams per liter (mg/L). Factors used to determine the water quality include the pH, the salinity, and the hardness (see Analyze the parameters of a watershed for more info). Generally, water near the surface is more saline and harder and the deeper the water, the more saline it becomes. The quality of groundwater is greatly affected by the soil, the precipitation water, and then conditions of the rocks where the groundwater flows. For example, places near the coasts have groundwater with more sodium chlorine, and places near industry have groundwater with sulfur and nitrogen compounds obtained from the air.
Groundwater is polluted by point sources and non-point sources. Point sources include livestock wastes, leaks and spills of chemicals or petroleum, septic tanks, road salt, sewage sludge, from landfills. Non-Point Sources are pesticides, fertilizers, and other contaminants. These contaminants will end up in streams, rivers, and wetlands (Environment Canada 2008).
Another environmental problem with groundwater is the excess pumping of water for agriculture resulting in changes in the hydrologic cycle. The rate of evaporation from underground has increased and the depletion of groundwater has occurred in many areas (Campbell and Reese 2001).
Explain how the speed of water and vegetation cover relates to erosion.
Clearly, when the speed of water is faster, there is more force and erosion. When the speed of water is slower, more of the water is absorbed by the soil and there is less erosion (Environmental Protection Authority 2008).Vegetation can slow down the process of erosion because its roots bind and stabilize to the soil. Without it, there is nothing to stop the soil from being eroded away.
Soil erosion is becoming a major environmental problem because when the soil is being eroded faster than it can be replaced, that place becomes infertile. Eventually, if no action is take to stop erosion, the area will become a desert ("Soil Erosion" 2005).
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